Making changes to your profile like answering more match
questions, posting journal posts (if you have that feature
available), taking tests, doing profile edits, adding pictures -
all will result in your profile showing up in people's homepage
'activity feed', so that's one way to keep on people's radar.

Personally I think it's a bit obsessive but I've seen women that
change their profile pics several times a week for apparently the
primary purpose of keeping their profiles showing up there.